Electric resistance furnace



May 22, 192 3. 1 1,456,107 c. L. IPSEN ELECTRI C RES ISTANCE FURNACE Filed May 28, 1921 mwg/mmmw A a mwii Fig. 4.

In\/entorI Carl L; Ipsen, y

His Attorney.

Patented May 22, 1923.

UNITED STATES PATENT OFFICE.

CARL L. IPSEN, OF SCHENEC'IADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC RESISTANCE FURNACE.

Application filed May 28, 1921.

To all whom it may concern:

Be it known that I, CARL L. IPSEN, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Resistance Furnaces, of which the following is a specification.

The present invention relates to electric resistance furnaces and comprises in particular an improved structure for supporting electric resistance heaters. 4

In Collins Patent 1,310,060, of July 15, 1919, a resistance-furnace is shown in which heavy ribbon-shaped resistors are mounted on refractory supports carried by ringshaped frames which are in turn mounted on refractory metal members imbedded in the furnace wall.

In the structure embodying my present invention the supporting structure has been greatly simplified by omitting the ringshaped frames without sacrificing the strength and durability of the support. My new supporting structure possesses decided advantages over the former support as for example, the provision of a structure whereby broken or defective insulators may be readily replaced without dismantling the support or even disturbing the neighboring parts. The novel features of my invention will be pointed out with particularity in the appended claims.

The accompanying drawing illustrates a preferred embodiment of my invention in an electric furnace. Fig. 1 is a perspective view of a recessed brick and a heater support assembled in position; Figs. 2 and 3 respectively comprisea vertical section and front elevation of a portion of a furnace wall with supports and heaters mounted in position; Fig. 4 is a perspective view of a spacer for keeping adjacent heater ribbons apart, and

Fig. 5 is a sectional View of a support.

The furnace as a whole has not been illustrated. It may be similar to the furnace shown in U. S, Patent 1,310,060. One section of the furnace wall is shown in Fig. 2 consisting of a metal shell 1 inside of which is a layer of heat insulating brick, 2, faced by a layer of highly refractory brick 3.

The heater support, as best shown in Fig. 1, is constituted by a flat hairpin shaped strip 5 consisting of suitable refractory material,- as for example, of nichrome, an

Serial No. 473,226.

alloy of nickel and chromium. The longer transverse axis of the support extends vertically to increase the stiffness of the support. The bight Or looped portion of the support 5 may be anchored or laid in the brick work of the wall in any convenient way, preferably by being set vertically in a channel 6 of a brick 7 which is laid in the wall of the furnace, as shown in Fig. 2. The projecting arms ofthe-support 5 may be notched as indicated. Upon them is mounted a perforated refractory insulator 8. The bore of this insulator may be shaped so as to engage with the notches of the support 5 as shown in Fig. 5, and the exterior of the insulator may be grooved to hold the heater ribbons 9 in a fixed position. The insulator 8 preferably is set close to the wall to brace the support 5 and prevent sagging. Intermediate the looped ends of the heater ribbon 9 a series of spacers 10 are provided also supported by blades set in the brickwork of the furnace. Fig, 3 shows an end-on view of one form of spacers. Resting upon the fixed spacers 10 is another set of floating spacers 11 which are not attached to the furnace wall but rest upon the edges of the spacers 10. The spacers 11 may be notched to engage the heater ribbons with greater security. The described construction enables the heater ribbon to expand and contract without causing electrical shortrircuiting or mechanical displacement and enable ready replacement of broken or defective members.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric resistance furnace comprising a furnace wall, flat metal strips mounted in said wall, the longer transverse axis of said strips extending vertically, refractory insulators mounted on said strips abutting said walL and resistance heaters mounted onsaid insulators.

2. An electric furnace comprising a furnace wall, a flat metal strip bent on itself having the closed end mounted in said wall and the arms projecting outwardly away from said wall, refractory insulators mountedon said arms and a resistance conductor mounted on said insulators.

3. An electric furnace comprising a refractory wall, a fiat hairpin shaped metal strip having the closed end anchored in said wall in a horizontal position, the longer transverse axis of said strip extending vertically, refractory insulators mounted on the arms of said strip and a resistance heater supported by said insulators.

4. An electric furnace support comprising a refractory wall member having a'slot, a refractory metal blade one portion of which is adapted to be locked in said slot while another portion projects away from said member, and a refractory insulator mounted on the projecting portion of said blade.

5. A heater ribbon support comprising a refractory Wall member having a looped channel, a hairpin shaped refractory metal blade laid in said channel the arms of said blade projecting outwardly from said member, and refractory insulators mounted on said arms.

6. An electric furnace support comprising a refractory wall body adapted to form part of a wall, a fiat metal strip anchored therein and projecting outwardly therefrom, and a refractory insulating member mounted on the projecting portion of said strip.

7. An electric furnace comprising a refractory walled enclosure containing semicircular slots, hair-pin shaped metal blades anchored therein and having notched arms projecting outwardly from said enclosure, perforated, refractory insulators constructed to engage with said arms, and having external grooves, ribbon-shaped electric resistors engaging with said grooves, and notched spacers located between the turns of said resistor, said spacers being movable with respect to said wall.

In witness whereof, I have hereunto set my hand this 27th day of May, 1921.

CARL L. IPSEN. 

